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Home >> Mazda >> 2019 >> CX-9 Signature >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Communication Devices >> On-Board Diagnostic - Front Body Control Module (FBCM) >> DTC B1143-13: IG2 Control Circuit Malfunction [Front Body Control Module (FBCM)] >> Diagnostic Procedure
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Diagnostic Procedure

DTC B1143:13 [FRONT BODY CONTROL MODULE (FBCM)] DIAGNOSTIC PROCEDURE

Step Inspection Action
1 VERIFY FRONT BODY CONTROL MODULE (FBCM) DTCs AGAIN Yes Go to the next step.
No Go to Step 7.
2 INSPECT START STOP UNIT CONNECTOR CONDITION
  • Switch the ignition off.
  • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
  • Disconnect the start stop unit connector.
  • Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
  • Is the connector normal?
Yes Go to the next step.
No Repair or replace the connector, then go to Step 6.
3 INSPECT FRONT BODY CONTROL MODULE (FBCM) CONNECTOR CONDITION
  • Disconnect the front body control module (FBCM) connector.
  • Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
  • Is the connector normal?
Yes Go to the next step.
No Repair or replace the connector, then go to Step 6.
4 INSPECT IG2 CONTROL CIRCUIT FOR OPEN CIRCUIT
  • Verify that the start stop unit and front body control module (FBCM) connectors are disconnected.
  • Inspect for continuity between start stop unit terminal 2D (wiring harness-side) and front body control module (FBCM) terminal 2U (wiring harness-side).
  • Is there continuity?
Yes Go to the next step.
No Refer to the wiring diagram and verify whether or not there is a common connector between start stop unit terminal 2D and front body control module (FBCM) terminal 2U.
If there is a common connector:
  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
  • Repair or replace the malfunctioning part.

If there is no common connector:
  • Repair or replace the wiring harness which has an open circuit.

Go to Step 6.
5 INSPECT START STOP UNIT Yes Go to the next step.
No Replace the start stop unit, then go to the next step.
(See START STOP UNIT REMOVAL/INSTALLATION .)
6 VERIFY THAT REPAIRS HAVE BEEN COMPLETED Yes Repeat the inspection from Step 1.
Go to the next step.
No Go to the next step.
7 VERIFY IF OTHER DTCs DISPLAYED
  • Are any other DTCs displayed?
Yes Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [FRONT BODY CONTROL MODULE (FBCM)] .)
No DTC troubleshooting completed.